Support for multiple discriminators on single type

[zawodskoj]

This PR allows to add multiple discriminator values for single subtype which can cover all of discriminators. This is required for compound discriminators (tuples for example) and allows to write converters like this

JsonSubtypesConverterBuilder
    .Of(typeof(DeviceEvent), nameof(DeviceEvent.Discriminator))
    .RegisterSubtype(typeof(MetalDetectingAlert), (EventType.ALERT, DeviceType.METAL_DETECTOR))
    .RegisterSubtype(typeof(DeviceFailureWarning), (EventType.WARNING, DeviceType.METAL_DETECTOR))
    .RegisterSubtype(typeof(DeviceFailureWarning), (EventType.WARNING, DeviceType.CAMERA))
    .Build()

[manuc66]

Hi,

Thanks for submitting a PR to this project

Could you please add some unit tests with serialization and deserialization ?

Does it also work with KnownSubTypeAttribute construct ?

And don't worry about the build failure related to SonarQube (it's a configuration problem)

[manuc66]

_addDiscriminatorFirst or _serializeDiscriminatorProperty ?

[zawodskoj]

Yes, it should be _serializeDiscriminatorProperty

[manuc66]

This kind of check is better suited in JsonSubtypesConverterBuilder (this class is internal)

[zawodskoj]

ConverterBuilder contains inverted dictionary, but we can add check for it anyway

[zawodskoj]

It should work with KnownSubTypeAttribute. Attributed converter does not serialize discriminator and does not require type-to-discriminator mapping

I can add tests later